English

Topological Hochschild homology of X(n)

Algebraic Topology 2017-09-01 v1

Abstract

We show that Ravenel's spectrum X(2)X(2) is the versal E1E_1-SS-algebra of characteristic η\eta. This implies that every E1E_1-SS-algebra RR of characteristic η\eta admits an E1E_1-ring map X(2)RX(2)\to R, i.e. an A\mathbb{A}_\infty complex orientation of degree 2. This implies that R(CP2)R[x]/x3R^\ast(\mathbb{C}P^2)\cong R_\ast[x]/x^3. Additionally, if RR is an E2\mathbb{E}_2-ring Thom spectrum admitting a map (of homotopy ring spectra) from X(2)X(2), e.g. X(n)X(n), its topological Hochschild homology has a simple description.

Keywords

Cite

@article{arxiv.1708.09486,
  title  = {Topological Hochschild homology of X(n)},
  author = {Jonathan Beardsley},
  journal= {arXiv preprint arXiv:1708.09486},
  year   = {2017}
}

Comments

This short note has been on my website since 2015, but I noticed that it was cited recently, so thought I would give it a slightly more permanent home. As always, comments and feedback welcome. 2 pages